my dog had a leaky bladder for a couple of years, and it was really challenging because it made for a pee-smelling house. He did go on medication (can't remember the name anymore) which did work. A couple of years into him being medicated, on a whim I reduced his dosage, and even took him off it and he wasn't leaky anymore, so I'm not really sure what that was about.

I'm not sure if there's anything you can do about it diet or supplement-wise. I do know that it's more common in older females than males. I did wrap a towel around his mid-section, but that didn't stay on very long. I know dog diapers have come a long way, even in the 8 years or so ago that I had this problem (there weren't many diapers for dogs back then, at least not for big dogs).